Trk-IN-9 (Compound 12) is a potent inhibitor of TRK. Trk-IN-9 inhibits the proliferation of Km-12 cell lines. Trk-IN-9 induces the apoptosis of Km-12 cells in a concentration-dependent manner. Trk-IN-9 inhibits the phosphorylation of TRK to block downstream pathways. Trk-IN-9 has the potential for the research of NTRK-fusion cancers.